This invention relates generally to improvements to leverage the inherent separation capabilities of ribbon drive pumping apparatus to allow contaminant removal using a ribbon drive mechanism. More particularly, the present invention is a ribbon drive shaped as a spiral ribbon along the interior wall of a tubular conduit for causing water or other liquids to be pumped through the apparatus. A sorbent or bleed valve is located in the high frequency portion of the ribbon adjacent the pump inlet for contaminant removal.
Pumped liquids often include contaminants that require removal to prevent adverse effects such as blockage, hazardous conditions (fire, explosion, poison, etc.), corrosion, impeller pitting, etc. For example, pumped petroleum products are often contaminated with water and cryogenic liquids are often contaminated with hydrogen.
The prior art usually addresses these contaminants by either providing separate separation systems or by providing in-line filtering. However, separate separation systems can be costly and complicated and in-line filters can cause undesirable pressure drops and can become clogged.
Therefore, what would be useful would be a pumping system capable of overcoming these limitations by having an integral contaminant removal means.
The present invention is just such a system that differs significantly from the inventions discussed above. The present invention generally comprises a ribbon drive with a high frequency coil at the intake end at point A with the frequency decreasing along the length of the tube to point B, wherein a sorbent and/or bleed valve is located within the ribbon drive proximate the intake to leverage the ribbon drive""s inherent separation capabilities.
As discussed more fully below, the ribbon drive pumping apparatus consists of a ribbon-like curved shape composed of metal or other suitable material. The ribbon can be of a xe2x80x9ccentral designxe2x80x9d wherein it is attached at an inner edge to a rotating central shaft and an outer edge extends nearly to a fixed containment tube, leaving a small clearance to allow rotation. The ribbon can also be of axe2x80x9cperipheral designxe2x80x9d wherein an outer edge is attached to the interior periphery of a spinning containment tube or a series of peripheral rings rotating within a fixed cylindrical containment tube, said spinning or fixed containment tube and said rings having a constant diameter for the length of the containment tube. A sorbent and/or bleed valve is located within the ribbon drive proximate the intake, where contaminants can be centrifugally separated from the primary pumped liquid.
It is an object of the present invention to create a pumping apparatus providing contaminant removal with significantly decreased outlays of capital for facilities construction compared to that presently required.
It is a further object of the present invention to create a pumping apparatus with integral contaminant separation.
It is a further object of the present invention to create a pumping apparatus that can remove contaminants without pressure loss.
It is yet another object of the present invention to provide a system and method useful for removing contaminants from cryogenic liquids (i.e., H2 or noble gases from liquid nitrogen, liquid oxygen, etc.) and liquid petroleum products (i.e., water from crude oil, LNG, etc.).
It is another object of the invention to provide a quiet and efficient pump due to both reduced cavitation and improved gas removal.
It is another object of the present invention in a peripheral design embodiment to allow the pumping of largexe2x80x9ccontaminantsxe2x80x9d such as live fish.
The ribbon drive pumping apparatus of the present invention consists of a ribbon-like curved shape, composed of metal or other suitable material, as disclosed in co-pending application Ser. No. 09/628,787, now U.S. Pat. No. 6,357,998.
A key element of the present invention is that there is a change in the frequency of curves of the ribbon drive, which proceeds from a high frequency (many coils per unit length) at the leading portion of the apparatus to a low frequency (few coils per unit length) at the trailing portion of the apparatus. The apparatus has an increasingly stretched frequency of coils as one proceeds down the length of the interior periphery of the containment tube. For example, in appearance, at the intake point for the water at point A, the apparatus would present a tightly curved angle for the coil, with said angle being nearly vertical to the intake of water passing through the apparatus and changing/progressing to a much more gradual curve at an angle that might approximate 30 degrees to the horizontal at the discharge point of the containment tube at point B.
The initial tight curves (the high frequency front entry section of the coil) provide centrifugal separation of material being pumped within the forward portion of the containment tube based on the density differences.